As is well known in the art, various eye disorders, such as diabetic retinopathy, vascular occlusion, neovascularization and age macular degeneration, can, and in most instances will, have an adverse effect on the retina. Indeed, if not treated at the appropriate stage, noted diseases, particularly, diabetic retinopathy, can lead to severe losses in vision.
Various methods and systems have thus been developed to aid in the diagnosis of the noted eye diseases. The method often employed by an eye care specialist, such as an ophthalmologist, is to examine the ocular fundus (the inside back surface of the eye containing the retina, blood vessels, nerve fibers, and other structures) with an ophthalmoscope.
The ophthalmoscope is a small, hand-held device, which, when appropriately positioned, shines light through a subject's pupil to illuminate the fundus. By properly focusing the light reflected from the subject's fundus, an examiner can observe the fundus structures.
As is well known in the art, examination of the ocular fundus can also be achieved using a fundus or slit lamp camera. Illustrative are the apparatus and systems disclosed in U.S. Pat. Nos. 5,713,047, 5,943,116, 5,572,266, 4,838,680, 6,546,198, 6,636,696, 4,247,176, 5,742,374 and 6,296,358.
Various method and systems have also been developed to treat eye disorders, such as diabetic retinopathy, glaucoma and age macular degeneration. One known method of treating the noted eye disorders, as well as retinal detachment, is laser coagulation of predetermined biological structures of the eye, such as the retina.
As is well known in the art, during laser coagulation of an eye structure, laser energy is transmitted to the structure to effect coagulation thereof. A typical laser coagulation system thus includes a laser energy or beam source, such as a beam projector, a slit image projector or lamp for forming a slit image on the eye, and observation equipment for observing the slit image and laser spot(s) in the eye. Illustrative are the laser coagulation systems disclosed in U.S. Pat. Nos. 4,759,360 and 4,736,744.
A major drawback associated with each of the noted conventional systems, as well as most known laser coagulation systems (and associated methods), is that the conventional slit lamp systems require a contact lens to neutralize the refractive power of the cornea. A contact lens is also necessary to provide a variable field of view of the retina up to 130°.
As is well known in the art, the contact lens must be appropriately positioned on the surface of the cornea and held at the desired position by the specialist, e.g., surgeon, while looking through the slit lamp microscope.
During this conventional laser coagulation procedure, the contact lens is positioned on the cornea, and held in position by the surgeon so as to permit the surgeon to view the retina through the slit lamp microscope during the laser application to the retina. In all conventional contact systems, the field of view is limited (e.g., maximum 50-60 degrees) and the surgeon is required to move the contact lens from one side of the eye to the other side of the eye during the procedure, and the patient is also required to move his or her eye, in order to permit the surgeon to see the peripheral retina.
There are several drawbacks associated with the use of a contact lens during laser coagulation. A major drawback is that the use of a contact lens requires topical anesthesia and a dilated pupil for laser application. As is well known in the art, a contact lens can, and in many instances will, cause corneal abrasion on an anesthetized cornea.
A further drawback associated with conventional laser coagulation procedures is that the laser procedures are dependent on the steadiness of the physician's hands and the subject's head.
Another apparatus that is often used for laser energy delivery to the peripheral retina is the indirect ophthalmoscope. Use of the indirect ophthalmoscope requires a physician to hold an appropriate convex lens in front of the eye (pupil) with one hand to focus the laser beam on the retina, while the eye is indented with another hand to bring the peripheral retina into the field of view for laser application.
In the indirect ophthalmoscopy technique, which is an alternative conventional method, the physician (i.e., surgeon) does not place a contact lens on the cornea, but rather he or she has to indent the peripheral part of the eye with an indenter (or scleral depressor) to bring the peripheral retinal areas into view, and additionally, the patient has to move the eye side to side.
Although laser delivery with an indirect ophthalmoscope eliminates the need for a contact lens, there are still drawbacks and disadvantages associated with use of an indirect ophthalmoscope. A major drawback is that during laser delivery (and, hence, coagulation of a desired eye structure), the ophthalmoscope is often carried on the physician's head for 30-60 mins. This extended period causes extreme fatigue for the physician.
The indentation of the eye for the extended period is also very unpleasant for the subject or patient.
A further drawback associated with the use of an indirect ophthalmoscope for laser coagulation is that the indirect ophthalmoscope does not provide a retained record or documentation for future evaluation. Further, in most instances, the subject typically requires subsequent fundus photography.
None of the abovedescribed conventional methods are suitable for remote laser application because they are limited in their field of view (typically 50-60 degrees). Also, the eye movement that is needed with these systems to view the entire retina renders them unsuitable for remote applications.
It would thus be desirable to provide non-contact systems and methods for laser coagulation of eye structures to treat eye disorders, and are capable of being effectively utilized to treat patients located at a remote site.
It is therefore an object of the present invention to provide non-contact systems and methods for laser coagulation of eye structures that substantially reduce or overcome the noted drawbacks and disadvantages associated with conventional contact-based laser coagulation systems and methods.
It is another object of the present invention to provide non-contact apparatus, systems and methods for laser imaging and coagulation of an eye structure.
It is another object of the present invention to provide non-contact apparatus, systems and methods for laser imaging and coagulation of the retina and its periphery to treat retina and choroideal disorders and/or diseases.